Polyphenyl ether stabilizers



3,151,080 POLYPHENYL ETHER STABELIZERS Wesley L. Archer, Midland, Mich, assignor to The Dow Chemical Company, Midland, Mich, a corporation of Delaware No Brawing. Filed Sept. 5, 1961, Ser. No. 135,724

3 Claims. (Cl. 252-515) stat-s wherein n is an integer from 2 to 6 or more. The employment of as little as 0.5% by weight of benzanilide, based on the total weight of the total composition, will reduce degradation of the polyphenyl ether lubricants and thus reduce the viscosity increase of the lubricant composition due to such degradation. Good results are achieved when employing from about 0.5 to about 1.5% by weight of benzanilide.

It has been found that the viscosity of the class of polyphenyl ethers increases when degradation occurs under high-temperature operations. Therefore, the increase in viscosity became a convenient measure of the degree of degradation which occurs in polyphenyl ethers during high-temperature tests wherein oxygen was intro duced to simulate actual operation as a lubricant in various systems. The use of viscosity as a measure of degree of degradation and/or stabilization resolved itself readily to the mathematical equation for percent improvement of stabilization according to the following equation:

K1512 X 100 Percent stabilization have the meaning above assigned and is calculated as above set forth.

3,151,080 Patented Sept. 29, 1964 ice The following example illustrates the present invention but is not to be construed as limiting.

Example 1 A 5 0 g. sample of bis(phenoxyphenyl)ether containing 1% by weight of benzanilide (heated on a steam bath to dissolve the benzoate) was heated at 600 F. for 24 hours while bubbling 3 l. of air per hour through a sparger near the bottom of the liquid. The initial and final viscosity was determined by an Ostwald viscometer tube. An uninhibited check was treated in the same manner. The inhibited ether percent stabilization when compared to the check sample (uninhibited ether) was found to be 53.

I claim:

1. A high-pressure, high-temperature lubricant composition consisting essentially of the polyphenyl ether having the formula tb lttl o tets wherein n represents an integer from 2 to 6, and from 0.5 to 1.5% by weight based on the total composition of benzanilide.

3. A high-pressure, high-temperature lubricant composition consisting essentially of the polyphenyl ether having the formula stat-o wherein n represents an integer from 2 to 6, about 1.0% i

by weight based on the total composition of benzanilide.

References Cited in the file of this patent UNITED STATES PATENTS 1,789,302 2,940,929 7 Diamond June 14, 1960 Calcott a a1 Jan. 30, 1931 

1. A HIGH-PRESSURE, HIGH-TEMPERATURE LUBRICANT COMPOSITION CONSISTING ESSENTIALLY OF THE POLYPHENYL ETHER HAVING THE FORMULA 